A ramp construction for the above purposes has been described in applicant's International Patent Application WO 0/02667, which is hereby incorporated by reference. This modular construction comprises basically two kinds of elements, ramp elements with a flat bottom surface and an upper surface, at least a portion of which is inclined at an angle relative to the bottom surface, and tile elements of a generally box-shaped geometry which can be placed underneath said ramp elements to form a composite modular ramp construction. Modules are attached to adjacent modules by means of dowel elements that are passed through holes in a given element and into mating holes in an adjacent element underneath the given element. When adjacent elements are attached to each other in this manner it is however very difficult at remove said dowel elements again in order to release adjacent elements from each other.
As the height (thickness) of the modules described in WO 0/02667 is fixed, difficulties may arise when a ramp construction as described in this document has to be adapted to the height of a given obstacle on a floor, such as a doorstep. Consequently, a vertical level difference between the highest level of the ramp construction and the height of for instance a doorstep may exist, which level difference could make it difficult, or at least uncomfortable, for a person sitting in a wheelchair to pass over the doorstep. This is only one situation, where such level differences will prove problematic. Another situation would be when a heavy object should pass a doorstep or other obstacle on a floor or ground portion carried on a cart or trolley.
A further wedge system is known from EP 0 622 281. This system comprises two cooperating wedge parts which are to be assembled in order to provide the desired wedge. Each wedge part is provided with means in the shape of recesses in upper surface of the lower part and matching protrusions in the lower surface of the upper part, such that the two parts may be superposed and the means engage. Furthermore to maintain the wedge parts in their desired position relative to each other a bolt or the like is used to fastend the two parts to each other.
Basically this construction is very complicated. In order to provide a wedge the parts must be assembled correctly, and adjusted to the desired angle. Furthermore in addition to the number of parts involved the assembly also requires working time and thereby an extra expense.